2000 GMC, Jimmy 4 wd.
Since I bought the truck the rear wiper never worked. I figured oh well. Then the light on the dash, hatch open would not turn off. I oiled the hatch lock and the light went off for a day. I took off the big plasic trim to access the mechanism. I found the latch arm was not returning far enough to signal the hatch was fully closed. I put a small 1 inch long spring on the arm and the light was off. To my surprise the rear wiper now workes. Apparently it has a power cut off to the wiper motor if the hatch in not closed. That was a bonus day, two problems fixed with one solution.